This light pod is made to hold a standard GU10 light.
The 2 pieces are held together with a M4x12 bold and nut allowing the pod to swivle. The GoPro mount means you can use any GoPro style attachemnt to hold the light pods.
The pod is made to hold a standard GU10 light socket which can be found on amazon. The socket can be either glues in or held in using a M3 nut and bolt.
If you are using a LED light PLA will be fine use. If you use a Halogen bulb you may want to use ABS or PETG to handle the heat generated.